package com.rd.student.ruanjian.class3.gaochenxi.NumberTen;

import java.util.Scanner;

public class NumberTen {
      public static void main(String[] args) {
            System.out.println("请输入一个罗马数字：");
            Scanner scanner=new Scanner(System.in);
            String ch=scanner.next();
            String value = String.valueOf(getValue(ch));
            int roman = Roman(value);
            System.out.println(roman);

      }
      public static int Roman(String s) {

            int sum = 0;

            int preNum = getValue(String.valueOf(s.charAt(0)));

            for (int i = 1; i < s.length(); i++) {
                  int num = getValue(String.valueOf(s.charAt(i)));
                  if (preNum < num) {
                        sum -= preNum;
                  } else {
                        sum += preNum;
                  }
                  preNum = num;
            }
            sum += preNum;
            return sum;
      }

      public static int getValue(String str) {
            switch (str) {
                  case "I":
                        return 1;
                  case "V":
                        return 5;
                  case "X":
                        return 10;
                  case "L":
                        return 50;
                  case "C":
                        return 100;
                  case "D":
                        return 500;
                  case "M":
                        return 1000;
                  default:
                        return 0;
            }
      }
}
